Electrical Engineering - Series-Parallel Circuits - Discussion
Discussion Forum : Series-Parallel Circuits - General Questions (Q.No. 9)
9.
A certain Wheatstone bridge has the following resistor values: R1 = 10 k
, R2 = 720 , and R4 = 2.4 k. The unknown resistance is
, R2 = 720 , and R4 = 2.4 k. The unknown resistance is24
2.4
300
3,000
Discussion:
28 comments Page 2 of 3.
Puja said:
9 years ago
But, If we apply the formula R1/R2 = R3/R4 then answer is different from the answer of R1* R2= R3 * R4 formula. Please explain me again which method is right.
VIJAY said:
10 years ago
R1*R2 = R3*R4.
There for R3 = (R1*R2)/R4 720 ohm = 0.72 k ohm.
10k ohm*0.72k ohm/2.4k ohm.
3k ohm = 3k*1000.
Answer: 3000 ohm.
There for R3 = (R1*R2)/R4 720 ohm = 0.72 k ohm.
10k ohm*0.72k ohm/2.4k ohm.
3k ohm = 3k*1000.
Answer: 3000 ohm.
Megha said:
1 decade ago
Nice answer.
Parneet kaur said:
1 decade ago
@Ankit Tiwari.
Your formula is wrong. The correct formula is r1*r2=r3*r4.
Your formula is wrong. The correct formula is r1*r2=r3*r4.
Piya said:
1 decade ago
But in wheatstone bridge: R2/R1 = R4/R3.
Chetan said:
1 decade ago
In wheatstone bridge product of two opposite resistors is equal to the another product.
So R1*R2=R3*R4,
R1, R2, R4 are given, we need to find R3.
R3 = R1*R2/R4 = 10K*720/2.4K = 3000.
So R1*R2=R3*R4,
R1, R2, R4 are given, we need to find R3.
R3 = R1*R2/R4 = 10K*720/2.4K = 3000.
ROOPESH D M said:
1 decade ago
Data is insufficient. Because we get different values of resistance depends on the bridge circuit.
We can take R1*R2 = R3*R4.
Or R1*R3 = R2*R4.
Or R1*R4 = R2*R4.
In each case we get different values, so without circuit we can't decide the unknown resistance value.
We can take R1*R2 = R3*R4.
Or R1*R3 = R2*R4.
Or R1*R4 = R2*R4.
In each case we get different values, so without circuit we can't decide the unknown resistance value.
Ravi said:
1 decade ago
Formula: R1*R2 = R3*R4.
Therefore R3 = (R1*R2)/R4.
= (10k*720)/2.4 k.
= 3000 ohms.
Therefore R3 = (R1*R2)/R4.
= (10k*720)/2.4 k.
= 3000 ohms.
Nouman said:
1 decade ago
@Meenakshi : How do we find R1 ? when its already been given in the question.
Mahe said:
1 decade ago
In wheatstone bridge product of two opposite resistors is equal to the another product. Here R1 R2 and R3 wherever we can mention. So these kind of problems we need a circuit or figure.
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